QuestionI have a 92 yamaha virago 750 motorcycle. I put the bike up on its stand and run the bike and shift it through its gears without any issues. Once I get to the road it seems that once I reach 3rd and 4th gear the bike just wants to stall out and I can't get it started again until I wait about 5-10 minutes. Then the bike will start and the same thing will happen again. It seems to run fine going down the road until I get to 45 MPH then it just quits on me. I have replaced stator and the rectifier components and it seems that the battery if fully charged. Once the bike quits running and you try starting in the 5-10 minutes afterward it just turns over but won't fire. Any ideas for me?
AnswerHi Victor,
Your best bet is to try to isolate if
you are having a fuel or spark problem.
When it stops running stick a spare
spark plug in each of the plug wires
and see if it still has spark.
You will have to ground the plug body
on the engine.
If you have spark then you can focus on
the fuel supply.
This includes the tank air vent, tank fuel valve,
fuel pump, fuel filter and carb float valves.
If you have no spark then the focus will
be the ignition pickup or pulse coils inside
the left engine case and the ECU or transistorized
ignition module.
Sometimes the fix is simple as in the case
of a plugged tank air vent in the gas cap.
The fuel tank needs air or it will lock
up the fuel delivery.
If you open the cap and you hear air rush in
then the cap vent is plugged.
Your fuel pump may be failing or the filters
may be plugged up.
The last resort is usually a failing ignition
unit and they are expensive.
Usually if they fail the bike will
run erratically at all speeds or not run at all.
Your problem sounds like either a fuel problem
or maybe the ignition pickup coils cutting out.
See if you can figure out which system is
the problem and then it will be easier
to find the answers. (Fuel or ignition)
Let me know if you need more info.
Good luck!
Wayne S.
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